Sighting device



`March 2 1926.

v 1,575,606 J. B. HENDERsoN SIGHTING DEVI CE Filed July 26, 1919 2 Sheets-Sheet 1 March 2 v1926. 1,575,606

, J. B. HENDERSON l SIGHTING DEVICE 2 Sheets-Sheet 2 IN VEN TOR.

Filed July 26, 1,919

A TTORNE YS.

Patented Mar. 2, 1926.

EUNlE STATES Frio.V

JAMES BLACKLOCK HENDERSON, OF LEE, ENGLAND.

SIGHTING- DEVICE.

Application filed July 26, 1919. Serial No; 313,532.

To all whom 'it may concern:

Be it known that I, JAMES BLACKLOCK HENDERSON, a subject of the King of Great Britain, residing at 2 Cambridge Road, Lee,

in the county of Kent, England, have invented certain new and useful Improvements in Sighting Devices (for which I have led an application in England, No. 3147, March 2, 1917), of which the following is a specification. i

My invention consists in improvements in sighting devices such as gunsights,bomb-.

sights, photograph-ic sights and the like, which are used on board ships, aeroplanes, or other moving platforms, and while particularly applicable to that type of sight. which embraces an automatic tiring gear such as an electric switch which controls the instant of firing and which is closed by the angular motion' of the ship at the instant when the gun is elevated relatively to the line of sight to the target, at the required elevation for the range of theltarget, is also applicable generally to all cases where a sight controls the operation of a power circuit. or mechanism or member.

In any type of sight employed with the gun, a small error is introduced by the motion of the gun during the time interval which elapses between the closing of the firing circuit and the shot leaving the muzzle of the gun.

Various devices have beel hitherto roposed in connection with roscopic or pendulum controlled firing o guns, to advance the instant of firing before the targetI passes the cross wires in the gun sight. In one form of gyroscopic control, a sliding weight is mounted on one of the trunnions of the case of the gyroscope in order to displace the centre of gravity from the Cardan centreto effect displacement of one electric contact with reference to another to obtain the` necessary advance vof the instant of ring. l

According to the present invention I provide `means characterized by an elastically,

constrained gyroscope Iwhich is forced to partake of the angular motionpf the gun or other time controlled mechanismar nember, the strain on the gyro controlled mechanism beingI employed to roduce an angular advance of the circuit c osing device orof the instant of firing or other actuation, or to produce an angular elevation or depression of the line of collimation of the sighting telescope or equivalent, said angular ade Vance or elevation or depression being proportional to the velocity of roll at the instant.

In the accompanying drawings `several methods of carrying the invention into prac- 3 showing an alternative arrangement to' that shown in Figure 2, and Figure 4 showing, somewhat diagrammatically, the apparatus of Figure 1 applied to a gun.

Referring to Fig. 1, the firing circuit is closed by a switch consisting of two semicircular Contact plates 1 and 2 insulated from one another and separated by an insulating strip 3. Contact is made between the two plates by means of the dumb-bell roller 4 pivoted 1n the cross piece 6 which is again pivoted, as at 5, in the fork 7 which is carried by a switch Alever 8 pivoted on a fulcrum 9 and adapted to be stabilized by any suitable mechanism, such as a gyroscope as will hereinafter appear. The two contact wheels of the roller 4 have diameters proportional to the distances of the wheels from the pivot 9. It is therefore necessary to insure that the positions of the wheels shall not be inadvertently reversed, andfor this purpose one end 4of the roller 4 is of reduced diameter and passes through an elongated slot in the vertical portion ofthe fork.

The insulated contact plates 1 and 2 are carried by a lever 10 which is pivotedron a ball bearing 11 rconcentric with the pivot 9 of the switch lever' 8. The other end of the lever 10 carries a small gyroscope in its casing 12 which is pivoted on trunnions 13,13 in brackets 14, 14 rigidly attached to'the 'lever 10.

As shown most` clearly in Figure 4, a sight frame 40 is pivoted as at 41 to the cradle 42 of the mount for a gun 43 and -is adapted to be set by a worm 44 operated by a handle 45 through bevelI gears 46. The fulcrum 9 is fixed to the sight frame so that in its normal position it is perpendicular tothe plane of the trajectory of the projectile, the tiring of which is controlled by the switch, The lever 10 is constrained relatively to the sight frame by two springs 15 and 16 attached to a pin 17 on the lever 10 and to two pins 18 and 19 on the frame of the sight. The gyroscope is also constrained relatively to the frame of the sight by the con` necting rod 20 which connects a pin 2l on the gyroscope case to a pin 22 on the frame of the sight, the joints at both ends of the rod 20 being spherical joints. lIt will be obvious that the gyroscope 12 cannot oscillate about its trunnion axis 13-13 without causing the lever 10 to oscillate a corresponding amount about the axis 9, thereby advancing or retarding the ignition of the charge'in the gun. y

The roller 4 of the switch is stabilized by a gyroscope 47 supported in an inner ring 48 which in turn is supported onhorizontal trunnions 49 in an outer ring 50 which is mounted between the sight frame 40 and a bracket 51 attached to the frame. The ring 50 carries a post 52 which is connected by a link 53 to the free end of lever 8 upon which the roller 4 is mounted.

In the operation' of the apparatus described above the setting for range is effected by depressing the sight frame through an anglecorresponding to the elevation of ythe gun forvthe given range. The gun is then elevated, taking the sight with it, until the target is seen at the cross wires`of the sighting telescope which for the sake of simplicity has been omitted from Fig. 4.` The gun is then at ithe correct elevation. rlhe gun, sight frame and parts fixed thereon, including the lever- 10 roll with the ship, but the' switch lever 8 and roller 4 are stabilized by the gyroscope 47 through the rings 48 and 50, post 52 and link 53.

As a result of the torque applied to the gyroscope 12 bythe roll of the ship, the gy- -roscope will precess about its 'trunnion axis 13-13 through an angle proportional to the velocity of roll of the ship, and thus cause a movement of the arm 10 with respect to the vsight frame on account fof the connection 2() ,between the gyroscope and the frame. This will change the position of the contact plates 1 and 2 with respect to the roller- 4 and the direction of rotation of the gyroscope 12 is so chosen that the gun will be fired slightly ahead of the time at which it would` be fired by the movement of the roller 4 across the contact lates 1 and 2 by the motion of the latter wit respect tothe stablized switch lever 8. he parts lwill be so proportioned4 that the advance of the time of firing will be sufficient to compensate for the error duc 'to the motion'of the gun during the interval which elapses between the closing of the firing circuit an'd thedischarge of the projectile from the muzzle of the gun. In other Words, the effect of the gyroscope 12 is to produce a slight displacement of the contact plates 1 and 2 with respect, to the roller contact device 4 carried upon the yswitch lever 8 independently of the displacement between these plates and the contact device due to the compensating effect of the switchlever. v k

In Figure 2lthere is shown an arrangement for producing the same result by elevating ordepressing the line of sight of the sighting telescope by an amount proportional to the velocity of roll. The sighting telescope consists of an objective 23, yeyepiece 24, and prism combination 25.` In this arrangement the objective and eyepiece rollk 28. The upper end of the bell crank is constrained by the-two springs 29 and 30,

. the ends of which are connected to the pin 31 on the crank and to two pins32 and 33 fixed to the sight frame upon which the elementsdescribed above are mounted. The other en'd of the bell crank is Aconnected by the connecting rod 34 to the gyroscope casingv 12 as described in connection with Figure 1. The brackets 14 are however, in this case, attached to the sight frame rigidly. It is evident that as the slght rolls about the afxis 28 or any parallel axis, the gyro'scope causes the glass plate 26 to become -tilted through an angle proportional to the velocity of roll thereby tiltingthe line of sight up or down through a corresponding angle. It will be understood that firing mechanism like that shown in Figure 1, may be used in connection with the sighting telescope just described. Such mechanism may be controlled by the gyroscope which stabilizes the prism combination 25, in a manner similar to that shown in Figure 4, so that when the observer corrects for the tilt caused by the displacement of the plate 26 he will automatically advance the ignition by an amount proportional to the velocity of roll Iof the ship. For the sake of simplicity the other elements which would bev used in conjunction with the elements of Figure 2l have not v been shown in a figure similar to Figure 4 since the relation of all of these elements is obvious from the description and gures previously referred to.

Figure 3 vshows an arrangement equiva-A lent to that shown in Figure 2, but instead' of tilting a plate of glass the gyroscope moves a small-'angle prism 35 backwards and forwards along-the line of collimation. The

prism 35 is attached to the link 36 which links the crank 37 to the lever 38 so that the prism can be moved backwards and forwards along the line of collimation without being tilted. 'I'he connection to the gyroscope casing 12 is similar to that in Figure 2, and the action of the mechanism and its associated element is in other respects the same as the mechanism of that figure, the prism combination 25 being stabilized by anotherl gyroscope.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same isto be performed, I declare that what I claim is 1. In an apparatus for automaticallyV compensating for the angular movement of a controlled mechanism having a pair of elements movable with respect to each other, the combination of a gyroscope mounted upon a supporting axis and affected by the angular movement of the mechanism, constraining means for the gyroscope effective about said axis and a connection between the gyroscope and one of said elements whereby precession of the gyroscope resulting from such angular movement produces a displacement or' the element with respect to the other element proportional to the velocity of such movement.

2. In apparatus Jfor automatically compensating for the angular movement of a controlled mechanism during a predetermined interval of time, the combination of a member movably mounted with respect to the controlled mechanism, mounted upon a supportingaxis and adapted to partake of the angular movement of the mechanism, a `constraining connection between the gyroscope and the mechanism effective about said axis and means whereby the precession of thefgyroscope resulting from such movement produces a displacement of the member with respect to the mechanism.

In apparatus for automatically compensating for the angular movement of a controlled mechanism during a predetermined interval of time, the combination of a member movably mounted with respect to the controlled mechanism, a gyrosoope mounted upon the member and adapted to partake of the angular movement of the mechanism, and a constraining connection between the gyroscope and the mechanism whereby the precession of the gyroscope resulting from such movement produces a displacement of the member with respect to the mechanism.

4. In `apparatus for automatically compensating for the angular motion of a gun or the like' during itsV time of action,` the combination of a constrained gyroscope adapted to 4partake of the angular movement of the gun, and means whereby the precession of the gyroscope resulting from sucha gyroscope y and the gun eie'ctive about said artis, and -means whereby the precession of the gyroscope resulting from such movement produces a displacement of the member with respect to the gun.

6. In firing apparatus for guns, the combination of a sight frame attached to the gun, a lever movably mounted upon the sight frame, a pair of conducting members on the lever connected to the firing circuit of the gun, a contact device mounted upon the sight frame and adapted to cooperate with the conducting members in controlling the firing of the gun, a .gyroscope mounted upon the lever and a constraining connection between the gyroscope andthe said frame whereby precession of the gyroscope resulting from the movement imparted to it by movement ofthe gun produces adisplacement ofthe `conducting members with respect to the contact device toadvanc'e the time of firing of the' gun. c y K j` 7.'v In firing apparatus for guns, the combination of a sight frame attachedto the gun, a lever movably mounted on the sight frame, a pair of conducting members on the lever connected to the iring'circuitof the gun, a contact device mounted upon the sight frame and adapted to cooperate with the conducting members in controlling the firing of the gun, a gyroscope operatively connected to the contact device, a second gyroscope mounted upon the lever land a constraining connection between the second gyroscope and the frame whereby precession of the gyroscope resulting from the'novement imparted to it by movement-of the gun produces a displacement ofthe conducting members with respect to the contact device to advance the time'of firing of the gun.

8. In apparatus for automatically compensating for the angular movement of a controlled mechanism during a predeterminedinterval of time, the combinationot a gyroiscope mounted upon a supporting axis and adapted to partake of the angular movement of the mechanism, an element movably mounted upon the mechanism for use in controlling the same, and means including a constraini@ device effective about 'said axis whereby the precession of -the gyroscope resulting from the movement 'of the mechani-sm produces a displacement of the elemen with respect to the mechanism. D

9. In apparatus for automatlcally Hcompensating for the angular movement of al controlled mechanism during a predetermined interval of time, the combination of a member movably mounted with respect to the controlled mechanism, a device subject to torque about an axis parallel to the axis of the angular movement and responsively movable about an axis angularly disposed to the first named axis, a constraining connection between the device and the mechanism whereby the device will be affected by such angular movement and means whereby the eii'ect of the movement of the mechanism on by such angular movement, connectionsbe-4 the device produces a displacement of the member with respectto the mechanism.

11. In apparatus for automatically compensating for the angular motion of a gun or the like during its time of action, the combination of a device subject to torque about an axis-parallel to the axis of said angular motion and responsively movable about an axis angularly disposed to the first named axis, a constraining connection between the device and the gun whereby the device will be affected by such angular movement and means whereby the effect of the movement of the gun on the device produces an advance of the time offiring of the gun.

12. ln apparatu's `for automatically compensating for the angular movement of a controlled mechanism during a predetermined interval of time, the combination of' a member movably mounted with respect to the controlled mechanism, a member coacting with the first named member, la stabilizing device free from forced oscillations in phase with the disturbing forces introduced tween the device and the second Vnamed member, a second device subject lto torque about p an axis parallel to the axis of the angular movement and responsively movable about an axis angularly disposed to the first named axis, a constraining, connection between thc second device and the mechanism whereby the-device will be affected by the angular movement of the mechanism and means whereby the effect of the angular movement "of the mechanism on the second device proand the second named member, a second g roscope, a` constraining f connection between the rsecond gyroscope and the mechanism and means whereby precession of the second gyroscope resul-ting from angular movement of the mechanism produces relative displacement between the members.

14. In gun-firing apparatus for use on an angularly moving body, the combination ot' a sight frame attached to the gun, a lever movably mounted on the sight frame, a pail` of conducting members on the lever associated with the firing circuit of the gun, a contact device mounted upon the sight frame and cooperating with the conducting members in controlling the firing ,of the gun, a device free from forced oscillations in phase with the disturbing forces introduced by angular movement of the body, connections between the device and the contact device, a second device subject to torque about an axis parallel to the axis of the angular move-4 ment of the body and responsively movable about an axis angularly disposed to the first named axis, and mounted upon the lever and al constraining connection between the sec-' ond device and the frame whereby the device will be affected by such angular movement to produce a displacement of the conducting members with respect to the contact device to advance the time of firing of the gun.

` July 24, 1919.

J AMES BLACKLOCK HENDERSON. 

